FLORA, Ind. – New details are being released about what fire investigators might be looking for while reviewing a fatal fire case in Flora. It's been more than a year since four sisters tragically died in the fire.

Indiana State Police announced Wednesday that they requested the Indianapolis Fire Department do a peer review of the case. ISP investigators could provide specific information on this case, but did say peer reviews are common for larger cases.

The girls’ great-aunt, Jacqueline Partlow told FOX59, it's been an emotional year for her family.

"All this stuff is going back and forth, we don't know this, we don't know that. It's this. It's not that. It's just been a real roller coaster," Partlow said.

The fire has been ruled arson and it has raised many questions about how investigators handled the case and why it hasn't been solved.

"Still, there's no answer to what killed my nieces. We still don't know," Partlow said.

The review involves IFD going back into the home. Police won't say specifically what they're looking for or whether it will help solve the case.

"It's a fresh set of eyes look at that work to make sure that everything has been done completely that can be done," explained ISP Sgt. Rich Myers. "What they're gonna do is look at it and see, make sure everything that they would have done is done and that everything they see needs to be done is done or maybe look off this way at a different angle of it."

Family members said they agree a fresh set of eyes could be the break they need, but want to know why it took more than a year for it to happen.

"Why have you waited this long to review the evidence? What was you doing in between times, sitting around thinking something new was gonna jump off?" Partlow asked.

According to the National Fire Protection Association, a peer review is conducted by an outside agency. The code states "the author does not select the reviewers and reviews are often conducted anonymously."

One fire expert noted that a "technical review" might require investigators to go back and collect additional evidence. The NFPA code states during a peer review, investigators are "unlikely to be able to detect factual errors or incorrectly reported data." It also states "a proper technical review will provide the best means to adequately assess the validity of the investigation's results."

It's unclear if a peer review would result in any changes in the current investigation, based on the description of the act provided by NFPA.

State police said the ATF is no longer involved in the investigation. They confirmed ATF hasn't been involved since the first week after the fire. They wouldn't specify why.